Phonograph apparatus



Feb. 23, 1954 E. o. THCMPSON 2,670,210

PHONOGRAPH APPARATUS Original Filed April 18, 1945 3 Sheets- Sheet 1 I?J I PHONOGRAPH APPARATUS Original Filed April 18, 1945 3 Sheets-Sheet 2E. O. THOMPSON PHONOGRAPH APPARATUS Original Filed April 18, 1945 Feb.23, 1954 3 Sheets-Sheet 3 Patented Feb. 23, 1954 PHONOGRAPH APPARATUSElmer -0. Thompson, Gras Philco Corporation,

ration of Pennsylvania pril 18, 1945, Serial No.

Original application A Divided an 6, 1950, Serial No. 147,9

Claims.

This invention relates to the control of phonographs, and moreparticularly to the control of the driving motor for therecord-supporting turntable of a phonograph.

The present invention is especially applicable to phonographs of thetype in which the turntable is automatically stopped at the end of theplaying of a record and is started by the movement of a member which maybe under control of the user. An example of such a phonograph is thatshown in my prior Patent No. 2,508,845, issued May 23, 1950, of whichthis application is a division.

One object of the present invention is to provide a control arrangementfor a phonograph wherein a switch is controlled by movements of twomembers to eifect opening and closing of the switch.

Another object of the invention is to provide such a control arrangementfor use in a phonograph of the type above mentioned.

In a phonograph apparatus of the type referred to, the phonographmechanism is enclosed in a housing or casing having a slot-like openingfor insertion and removal of a record and also having a door associatedwith such opening. In the use of such apparatus, the user has only toinsert and remove records, and to open and close the door. As applied tosuch a phonograph, the present invention provides for automatic stoppageof the turntable at the end of the playing of a record, and furtherprovides for automatic starting of the turntable in response to closingmovement of the door.

The invention may be clearly understood by reference to the accompanyingdrawings wherein it is shown applied to a phonograph apparatus of thetype above mentioned.

In the drawings, v

Fig. l is a horizontal sectional view showing the phonograph apparatusin plan;

Fig. 2 is a perspective view of a slide member which serves to actuatecertain parts;

Fig. 3 shows the phonograph apparatus in side elevation with the door inclosed position and with a record on the turntable;

Fig. 4 is a detail view of the switch mechanism which controls theturntable operation, said view being taken along line 4-4 of Fig. l

Fig. 5 is a view of the same mechanism taken from the left side of Fig.4;

Fig. 6 is a plan view of the and Figs. 7 and 8 are explanatory views howthe switch is operated.

same mechanism;

showing more, N. Y., assignor to Philadelphia, Pa., a corpothisapplication March 63 Referring first to Figs. 1 to 3, the phonographmechanism is supported by a horizontal shelf or panel H3 within a casingor housing whose front wall is shown at H, complete illustration of thecasing being unnecessary. The phonograph tone arm and turntable areshown at I 2 and I3, respectively. The phonograph apparatus isinaccessible to the user during operation, and provision is made for theplaying of successive records simply by inserting them into a restrictedslot-like opening I4 adjacent the turntable [3. To this end, there isprovided a front wall member I5 which forms a part of the casingstructure and which has the record-insertion opening M therein. A recordI6 is shown on the turntable, and it will be noted that the recordprotrudes from the opening 14 into a recess l1 provided in member 15.The purpose of this arrangement is to enable insertion and removal ofthe record, as will be obvious. Adjacent the recess I7, and hingedlymounted on the outer part of the cabinet, is a manually operable door (8which occupies the door opening [9 when in closed position. When closed,the door conceals the record insertion opening I 4, and when opened itaffords access to the said opening.

As shown in Fig. 3, the turntable i3 is arranged in relation to therestricted opening l4 so that the upper surface of the turntable isslightly above the bottom surface of the opening. This permits therecord 16 to rotate freely with the turntable. It will be noted alsothat the door [8 has a recess 20 to accommodate a larger sized recordrepresented in dot-and-dash outline at 2!. A guide member 22 is securedto the wall In and extends therefrom above the turntable as shown. Thismember may take the form of a strip or plate of metal or other material,and its purpose is to insure proper insertion of the record, as will beseen later. The record is centered on the turntable by means of acentral pin or spindle 23 which is automatically retracted in responseto opening movement of the door I8,-

as will be described further hereinafter. The turntable is supported bymeans of a bearing structure 24 carried by the supporting shelf or panelIll. The record-centering spindle 23 is slidably mounted within the saidstructure. The turntable is driven in conventional manner (see Fig. 1)by means of a driving friction wheel 25 which is mounted on a pivotedbracket 25 and is maintained in engagement with the turntable flange bya spring 21, one end of which is attached to the bracket 26 while theother end is secured to a stationary pin 28 on the supporting panel In.The wheel 25 is driven by a smaller wheel or roller 29which in turn issuitably driven by the driving motor unit 30.

The tone arm I2 is mounted at the upper end of a spindle 3| (see Fig. 3)which is rotatably supported by a hollow post 32 mounted on thesupporting panel l0, so that the tone arm is adapted to move laterallyor horizontally with respect to a record on the turntable. The tone armis pivotally mounted on a horizontal pivot 33 so as to be verticallymovable with respect to the record. At its free end the tone arm carriesa suitable pick-up which may be of conventional form and which includesthe usual needle or stylus 34. At the lower end of the tone-armcarryingspindle 3|, there is provided an extending arm 35, the purpose of whichis to actuate the switch mechanism 36 at the end of the playing of arecord so as to automatically stop the rotation of the turntable, aswill be further described hereinafter. v

The record-centering pin and the tone arm are both controlled by themovements of the door l8. To this end, there is provided at the underside of the supporting panel ID a slide member 31 (see Fig. 2), which isslidably supported by the supporting panel. Member 31 has slots 38 and33 therein, by means of which it is slidably supported for rectilinearmovement forwardly and rearwardly. As shown in Fig. l, the supportingarrangement for the slide member 31 may include a pair of suitablefastening elements, such as screws 40 and M, which are carried by thesupporting panel I and which extend through the slots 38 and 39respectively. Thus it will be seen that the slide member 31 is supportedfor guided movement in the manner stated. At its forward end, the slidemember 31 has a depending lug 42 to which one end of a connecting link43 is pivotally connected. The other end of link 33 is pivotallyconnected to the door H3 at a point 44 (see Fig. 3) oifset from thehinge or pivot 45 of the door. When the door is opened, the link 43 ispulled forwardly so as to move the slide member 31 forwardly, and whenthe door is closed, the said parts are moved in the reverse direction sothat the slide member 31 moves rearwardly.

The tone arm I2 is actuated in response to movement of door I8 and slidemember 31 by means of the mechanism now to be described. As clearlyshown in Fig. 3 there is provided at the rear of the tone arm l2 anextending lug 46 carrying a screw 4'! to which one end of a flexiblecord 48 is attached. The cord passes around a pair of pulleys 49 and 50,and its other end is attached to one end of a helical spring whose otherend is secured to a screw 52 carried by 2. depending lug 53 on the slidemember 31. The pulleys 49 and 50 are rotatably mounted on a bracket 54secured to the under side of the supporting panel ill. The pulleys areso arranged that when a pull is exerted on the cord '48 by the forwardmovement of the slide member 31, the tone arm is subject to bothvertical and horizontal force components which lift the tone arm off ofthe record and swing it laterally to a position in which it may belowered onto the next record. Furthermore, the horizontal pivot 33 ofthe tone arm is so arranged in relation to the vertical pivotal supportthat the vertical force component is effective to lift the needle orstylus off the record before the tone arm is moved laterally, thuspreventing scratching of the record. When the slide member 31 is in itsrearward position, i. e. when the door I8 is closed, there is no ten-Jsion on the spring 5| and the tone arm is in its operative position.When the slide member is in its forward position, i. e. when the door I8is open, the spring 5| is placed under tension and the tone arm israised. The tension of the spring urges the tone arm laterally against astop post 55 having a cushion covering 55 thereon.

The post 55 is caused to limit the outward movement of the tone armaccording to the size of an inserted record by virtue of the mounting ofsaid post on one of a pair of feeler arms 51 and 58. As indicated by thesolid and dot-anddash representations in Fig. l, the feeler arms assumedifferent positions for difierent sized records, e. g. 10 inch and 12inch records. Since the present invention is not concerned with thefeeler arms and their further functions, further description thereof isunnecessary. For complete illustration and description of these elementsand associated parts reference may be had to the aforementioned patent.

As previously indicated the record-centering pin 23 is controlled by themovement of the door 13. For the purposes of this specification, itsuffices to note that vertical movement of the pin is effected by a camslot 59 provided in a depending plate 60 formed integrally with theslide member 31. A transverse pin 6|, connected to the pin 23, isdisposed in slot 59 and acts as a cam follower. The slot 59 is so shapedthat it lowers and raises the centering pin 23 in response to openingand closing movements of the door 18. Thus when the door is opened, thecentering pin is retracted to permit removal of one record and insertionof another. When the door is closed, the centering pin is projectedupwardly through the center hole of the inserted record.

Referring now to Figs. 4 to 8, there is shown in detail the switchmechanism 36 and its cooperation with certain of the parts hereinbeforedescribed, the purpose being to automatically stop the turntable at theend of the playing of a record and to start the turntable in response toclosing movement of the door [8.

The switch mechanism comprises an inverted U-shaped supporting bracket62 secured to the underside of the supporting panel [0, the undersurface of which is represented by the dot-anddash horizontal line inFigs. 4 and 5. The bracket 62 carries a rotatable shaft 63 which issuitably journaled for instance in bearings 64 and 65 which may formintegral parts of the supporting bracket. A mercury switch 66 is carriedby a supporting member 31 which is mounted on one end of the shaft 63 soas to be rotatable therewith. A pair of stops 68 and 69, formedintegrally with the supporting bracket 32, serve to limit the movementof the switch-supporting member 6'! as shown in Fig. 5. Member 31extends upwardly from the axis of rotation and carries a pin 10 at itsupper end, upon which an actuating element H is pivotally mounted. Theupper end of element H is provided with a friction hood I2 preferablyformed of rubber or like material. The element H functions cooperativelywith the previously mentioned arm 35 to actuate the switch mechanism atthe end of the playing of a record, as will be described presently.

A resilient member [3, which may take the form of a piece of spring wireor the like, is secured to the bracket 32 at M and is wound about asupporting projection or finger 15 on the bracket 62, and has its lowerend portion in frictional engagement with the shaft 63 so as to impose africtional drag on the shaft and thus tends to oppose rotation of theshaft. The purpose or this will appear presently. At the end of shaft 68opposite the switch 66, there is provided aresllient finger 16 which isengageable by a cam member '11 (see Fig. 2) formed integrally with theslide member 31, the purpose of which will also appear presently.

Referring again to Fig. 1, the arm '35, which extends from the lower endof the tone armsupporting spindle 3 i, has an enlarging and forming aplate 18 which is adapted to engage the friction hood [2, as shown inFigs. 7 and 8. The arm 35 is so positioned in relation to the tone armI! that the plate 18 engages the friction hood 12 when the needle orstylus engages the eccentric groove at the end of a record, the saidgroove being shown in Fig. 1 at 19. The eccentricity of the groove 19may vary from one record to another, and the switch mechanism isdesigned to insure operation of the switch regardless of such variation.

The operation of the switch mechanism may best be explained withspecific reference to Figs. 5 to 8. The mercury switch 66 is connectedin circuit with the turntable driving motor so as to control theoperation thereof, and during playing cl 2. record, the switch is in theposition of Figs. 5 and 7 in which it is closed, so that the turntabledriving motor is energized.

Prior to the engagement of plate 18 with the friction hood [2, theelement H is vertically positioned, as shown in Fig. 5, due to the factthat its supporting pin IE! is above its center of mass. As the needleor stylus approaches the eccentric groove at the end of the record, theplate 1'8, moving from left to right, as viewed in Figs. 5, 7 and 8,engages the friction hood I? and deflects the element H to a positionsuch as shown in Fig. 7. When the stylus enters the eccentric groove atthe end of the record, the plate 18 moves back and forth, as indicatedby the double head arrow in Figs. 7 and 8. The range of this oscillatorymotion of the plate 18 is indicated by the dotted line representation inFig. 6 and the associated double head arrow. Movement of the plate 18toward the left in Figs. '7 and 3 causes application of a force to thepin 10 through the upper portion of element H, which force moves theswitch support 6! counter-clockwise from the position of 7, as shown inFig. 8. If the eccentricity of the record groove is relatively great,the first left-hand movement of plate 18 may move switch 66 suflicientlyto open it. If the groove eccentricity is not so great, the element H isstepped progressively toward the left as shown 1 in Fig, 8, therebymoving the switch progressively until it opens. Thus the switch isopened even though the eccentricity of the record groove may vary fromone record to the next. The friction drag element 73 serves to maintainthe switch in any position to which it is moved.

During the playing of a record, the cam member 11 is inthe left handposition shown in Figs. 4 and 6. When the door I 8 is opened, after theplaying of a record, the cam member 7? moves to the right hand positionshown in dotted outline in Figs. 4 and 6, and during such movement theupper surface of the inclined cam member engages the end portion ofresilient finger 16. This would eil'ect actuation of the switchmechanism to open the switch 66 if the switch had not already beenopened by the action of the plate 18, as above described. Consequently,resilient finger 16, being in a raised position, is engaged by the upperpart of the cam member I1 and is de- 6 flected sufficiently to enableits end portion to ride over the upper part of the cam member as thelatter moves to the right hand position shown.

When the door I8 is closed to initiate the playing of another record, thcam member 11 moves to the left hand position shown in Figs. 4 and 6.During this movement, the lower face of the inclined cam member engagesthe finger l6 and moves it downwardly, thus causing rotation of shaft 53in a direction to close the switch 66 and thus energize the turntabledriving motor. During this operation, the resilient finger l6 rides overthe lower portion of the inclined cam member H to the position shown inFig. 4.

Thus the cam member 11 functions, in response to movement of the doorl8, to insure that the switch 66 is opened and to close the switch so asto start rotation of the turntable when the door is closed.

Considering the operation of the phonograph apparatus as a whole, let usassume that a record is being played, the door 18 being closed. At theend of the playing of the record, the switch mechanism 35 opens theswitch to stop the turntable in the manner just described. When the doorit is opened to remove the record which has just been played and toinsert a new record, the slide member 31 moves forwardly, and in doingso it performs several functions. It lifts the tone arm I 2 oil of therecord and moves it to a starting position above the marginal portion ofthe record through the action of the cord and pulley arrangement, ashereinbefore described. It also lower the record centering spindle 23 toits inoperative position. It also insures that the motor switch 65 isopened.

The user may now remove the record which has just been played and inserta new record. When the door [8 is closed, the rearward movement of slidemember 3! raises the centering spindle 23, closes switch 56 to startrotation of the turntable, and lowers the tone arm to bring the stylusinto engagement with the marginal portion of the record. The parts areso designed that these functions are performed in the order named. Theoperating cycle is now repeated.

While it has been assumed that the user desires to change records, aswill usually be the case, some instances the user may desire to repeatthe playing of a record. In such case he simply opens the door I 8 andthen closes it without changing records. The opening and closingmovements of the door eilect automatic operation of the parts to repeatthe playing of the record, as will be obvious from the foregoingdescription.

It should be noted also that the playing of a record may be interruptedat any time merely by opening the door iii, in which case the cam member18 will open switch. as hereinbefore described.

While the control arrangement of the present invention has beenillustrated and described with reference to a particular embodiment, theinvention is not limited thereto but is capable of various modificationsand other embodiments as will appear to those skilled in the art.

I claim:

1. In a phonograph having a motor driven turntable and an associatedtone arm, a switch support pivoted for movement about a horizontal axis,a pair of stops for said support establishing two positions thereof, amotor-controlling mercury switch carried by said support so as to beclosed when the support is in one of said positions and opened when thesupport is in the other of said positions, said support being in theswitchclosed position during the playing of a record, an actuatingelement pivotally mounted on said support at a point spaced from saidaxis, said element being pivoted above its center of mass so as to bebiased by gravity to a normal position, said element having a frictionsurface at one end, and a member connected to said tone arm and movablethereby in a path to deflect said element to an inclined position and toexert force thereon by engagement with said friction surface uponoscillatory movement of the tone arm at the end of the playing of arecord, whereby to move said support to the switch-opened position.

2. Apparatus according to claim 1, wherein said actuating element ismounted on said switch support above the axis of movement of the latter,and the upper end of said element is provided with a friction surface.

3. In a phonograph having a motor-driven turntable and an associatedtone arm, a switch support pivoted for movement about a horizontal axis,a pair of stops for said support establishing two positions thereof, amotor-controlling mercury switch carried by said support so as to beclosed when the support is in one of said positions and opened when thesupport is in the other of said positions, said support being in theswitchclosed position during the playing of a record, an actuatingelement pivotally mounted on said support at a point spaced from saidaxis, said element being pivoted above its center of mass so as to bebiased by gravity to a normal position, said element having a frictionsurface at one end, a member connected to said tone arm and movablethereby in a path to deflect said element to an inclined position and toexert force thereon by engagement with said friction surface uponoscillatory movement of the tone arm at the end of the playing of arecord, whereby to move said support to the switch-opened position, andmanually-operable means for moving said support to the switch-closedposition for commencement of the next record-playing operation.

4. In a phonograph having a motor-driven turntable and an associatedtone arm, a switch support pivoted for movement about a horizontal axis,a pair of stops for said support establishing two positions thereof, amotor-controlling mercury switch carried by said support so as to beclosed when the support is in one of said positions and opened when thesupport is in the other of said positions, said support being in theswitch closed position during the playing of a record, an actuatingelement pivotally mounted on said support at a point spaced from saidaxis, said element being pivoted above its center of mass so as to bebiased by gravity to a normal position, said element having a frictionsurface at one end, a member connected to said tone arm and movablethereby in a path to deflect said element to an inclined position and toexert force thereon by engagement with said friction surface uponoscillatory movement of the tone arm at the end of the playing of arecord, whereby to move said support to the switch-opened position, asecond actuating element connected to said support, and amanually-controllable slide member having means engageable with saidsecond element to actuate said support to the switch-closed position forcommencement of the next record-playing operation.

5. In a phonograph having a motor-driven turntable and an associatedtone arm, a rotatable horizontal shaft, a switch support carried by saidshaft, a pair of stops for said support establishing two positionsthereof, frictional drag means engaging said shaft to restrain saidsupport in either of said positions, a motor-controlling mercury switchcarried by said support so as to be closed when the support is in one ofsaid positions and opened when the support is in the other of saidpositions, said support being in the switch-closed position during theplaying of a record, an actuating element pivotally mounted on saidsupport at a point spaced from said shaft, said element being pivotedabove its center of mass so as to be biased by gravity to a normalposition, said element having a friction surface at one end, a memberconnected to said tone arm and movable thereby in a path to deflect saidelement to an inclined position and to exert force thereon by engagementwith said friction surface upon oscillatory movement of the tone arm atthe end of the playing of a record, whereby to move said support to theswitch-opened position, an actuating finger connected to said shaft, anda manually-controllable slide member having means engageable with saidfinger to actuate said support to the switchclosed position forcommencement of the next record-playing operation.

ELMER O. THOMPSON.

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